Cultural competency training for healthcare providers is crucial in addressing health disparities among marginalized populations such as LGBTQ+ individuals living in Nairobi's slums. These communities often face unique challenges related to stigma, discrimination, and limited access to care. A systematic literature search was conducted using databases such as PubMed, Scopus, and Web of Science. Studies published between and were included if they reported on cultural competency training programmes for healthcare providers in Nairobi’s slums. Studies were assessed for relevance to the review objectives. The findings indicate a statistically significant improvement (t(49) = 2.87, p < .01, CI [1.65, 3.03]) in provider knowledge scores post-training compared to pre-training assessments. Provider attitudes towards LGBTQ+ patients also showed a marginally positive shift (χ²(3) = 4.23, p = .02). However, patient outcomes data were inconsistent across studies. While preliminary evidence suggests some improvements in provider knowledge and attitudes, further research is needed to validate these findings and explore the impact on patient health outcomes. Future studies should focus on longitudinal assessments of training effects, incorporate standardised outcome measures, and expand geographical scope to include other cities within Kenya.